Published online by Cambridge University Press: 20 November 2018
In (2) Sinkhorn showed that corresponding to each positive n × n matrix A (i.e., every aij > 0) is a unique doubly stochastic matrix of the form D1AD2, where each Dk is a diagonal matrix with a positive main diagonal. The Dk themselves are unique up to a scalar multiple. In (3) the result was extended to show that D1AD2 could be made to have arbitrarypositive row and column sums (with the reservation, of course, that the sum of the row sums equal the sum of the column sums) where A need no longer be square.
This author was partially supported by NASA grant NGR-44-005-037.
This author was partially supported by NASA grants NGR-44-005-037 and NGR-44-005-021.